1. Field of the Invention
The present invention relates to an air direction-changing portion of an air blower in a vehicle air conditioning system.
2. Description of the Related Art
In a conventional vehicle air conditioning system, a front seat air conditioning unit integrated with a rear seat air temperature adjustment portion and a rear seat air direction changing portion are known. The air conditioning unit is generally located behind an instrument panel at a forward area of the passenger compartment.
Since such an air conditioning unit shares one heater core in adjustment of the temperature of the air blown toward the front and rear seats, a rear seat cool air bypass passageway is disposed below the heater core. As a result, as shown in FIG. 6, a rear seat hot air inlet 34, into which hot air is introduced after having passed through the heater core, is disposed at an upper position, whereas a rear seat cool air inlet 33, into which cool air from a rear seat cool air bypass passageway 30 is introduced, is disposed at a lower position, the positions being relative to each other.
The air conditioning unit is also designed to allow a rear seat air mix door 31 to adjust the airflow ratio between the hot air from the rear seat hot air inlet 34 and the cool air from the rear seat cool air inlet 33, thereby adjusting the air temperature blown toward the rear seats.
On the other hand, in a rear seat blow mode-changing portion 35, a rear seat face opening 37 is disposed at an upper location, whereas rear seat foot openings 38 are disposed at a lower location, relative to each other. This is because a rear seat face duct (not shown) connected to the rear seat face opening 37 is disposed at an upper location, whereas rear seat foot ducts (not shown) connected to the rear seat foot openings 38 are disposed at a lower location.
FIG. 6 illustrates a bi-level mode selected as a rear seat blow mode, where a rear seat blow mode changing door 39 comprising a butterfly door formed in the shape of the Japanese character “(he)” is operatively rotated to a position at which both, the rear seat face opening 37 and the rear seat foot opening 38, are simultaneously opened.
In the aforementioned arrangement, however, the hot air from the rear seat hot air inlet 34 and the cool air from the rear seat cool air inlet 33 are separated into an upper and a lower portion by means of the plate surfaces of the rear seat air mix door 31 and the rear seat blow mode changing door 39. This causes most of the hot air from the hot air inlet 34 located at the upper location to flow through a passageway above the plate surfaces of both the doors 31, 39 into the rear seat face opening 37 located at its upper location. On the other hand, this also causes most of the cool air from the cool air inlet 33 located at the lower location to flow through a passageway below the plate surfaces of both the doors 31, 39 into the rear seat foot openings 38 located at the lower location.
For this reason, in the rear seat bi-level mode, the temperature of the air blown toward an occupant's face becomes higher than the air temperature blown toward an occupant's feet, thereby providing a blown air temperature distribution that is opposite to a head-cooling foot-heating blown air temperature distribution. Accordingly, this temperature distribution causes rear seat passengers to feel cold at their lower bodies and hot at their upper bodies.
The aforementioned problem could be overcome by locating the rear seat face opening 37 at a lower location and the rear seat foot openings 38 at an upper location. However, this may in turn require the rear seat face duct to be bent upwardly from the installed location of the rear seat face opening 37 (from the lower location) as well as the rear seat foot ducts to be bent downwardly from the installed location of the rear seat foot openings 38 (from the upper location).
Consequently, this may lead to an increase in pressure loss (pressure loss caused by bending) of the rear seat face duct and the rear seat foot ducts, thereby raising another problem of reducing the airflow amount directed toward the rear seat. This may also make it impossible to provide bends in both the aforementioned ducts due to the restriction of vehicular installation mounting space. Accordingly, the aforementioned measures of disposing the rear seat face opening 37 at a lower location and the rear seat foot openings 38 at an upper location are impractical.